It's not grossly inaccurate. It's working as designed.

What Randy said is that he estimated that he could get maybe 40 more miles after the MTE says 0. Randy is right in that he can really go farther after the MTE gets to 0 -- but it's not a good to assume a specific number.

Almost all car manufacturers want to make sure that there is, in fact, some useable gasoline left in the tank when the guage hits empty. This is because the know people would push it and don't really want you to run out of gas. They figure when the MTE reads 0 miles to empty and the needle is parked solidly on 'E' that you'd think maybe it'd be a good idea to get more gas -- but maybe that's just me. It would be a really BAD thing if the car ran out of gas when the guage still reads 1/8 tank and the MTE says you can go another 50 miles.

How much depends on the car or it's maker. It's usually somewhere around 1-3 gallons - though I wouldn't assume any.

If your guage says 'E' (or less) and your MTE says '0 miles to empty' and you run out of gas, it is your fault. Sorry -- no blaming the manufacturer. They told you that you had no reliable amount of gas left, you ignored it, you gambled, you lost.

If your guage says you have more than 'E' and your MTE says you still have many miles to go to empty and then you still run out of gas, you have a legitimate gripe and they should fix it.